American winged orbital launch vehicle. Lockheed investigated the economics of reusable launch vehicles for crews and light space station cargo during the early 1960s. Anticipated manned space activities in the 1970s included a two-phase Earth-orbital space station program, a lunar base, an early Mars mission, plus later Mars/Venus missions. Lockheed proposed four possible launch systems to support the scenario, ranging from System I, a 6-man Apollo CSM/Saturn-IB vehicle, to a fully reusable System IV with a ramjet-rocket booster.

System I appeared to be uneconomical as a high-volume manned transportation system even if the crew capsule could be reused 10 times. Lockheed's preferred System II would have retained the Saturn IB booster but replaced the Apollo with a new reusable DynaSoar-like10-man spaceplane that could be reused 500 times.

The fully reusable options were horizontal takeoff / horizontal landing two-stage-to-orbit designs launched from a ground accelerator sled. The System III booster was rocket-powered while the System IV booster used in-flight liquid oxygen collection and ramjet propulsion. The third stage spaceplane from System II was standard for the reusable systems as well. After deploying the third stage the reusable vehicles would fly orbit-once-around missions before returning to the launch base.

The System III and IV requirements were as follows:

95% mission reliability (0.1% vehicle attrition rate).

2950 kg payload and 10 passenger capability.

7.5 day minimum turnaround between missions (11-23 days nominal).

Mission life of 500 flights.

Flight rates of 100-300 missions per year in 1973-80.

System II would have cost $0.6 billion in FY 1964 dollars to place 250 passengers in orbit per year aboard 25 flights. System I would have cost. $0.95 billion per year to deliver the same number of passengers on 40 flights.

The estimated operating cost for the reusable systems ranged between $ 6.8 million per mission at a flight rate of 50 flights per year to $1.275 million at 400 flights per year in FY 1964 dollars. System III and System IV appeared to be equally cost competitive, but the development cost and risk would be lower for the all-rocket booster concept.

Lockheed Space Taxi American manned spaceplane. Study 1963. Lockheed investigated the economics of reusable launch vehicles for crews and light space station cargo during the early 1960s. Lockheed proposed a new reusable 10-man spaceplane as a follow-on to the Apollo CSM. More...

Winged In the beginning, nobody (except Jules Verne) thought anybody would be travelling to space and back in ballistic cannon balls. The only proper way for a space voyager to return to earth was at the controls of a real winged airplane. More...